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US 12,750,979 B2Granted
Clamped annealed pyrolytic graphite heat spreading
AssigneeRaytheon Company
InventorAndrew J. Pitts
Life of this patent
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Abstract
A heat spreader is provided and includes a core of orthotropic material having first and second preferred directions of thermal conduction, a top plate, a bottom plate and pyrolytic graphite sheets (PGSs). The PGSs are interposed in a compressed state as a thermal interface material (TIM) between the core and the top plate and between the core and the bottom plate in a compression direction aligned with at least one of the first and second preferred directions of thermal conduction.
Claims13
A heat spreader, comprising:
- a core of orthotropic material having a preferred direction of thermal conduction;
- a top
- plate;
- a bottom plate;
- stoppers disposed on the bottom plate in a compression direction;
- screws;
- and
- pyrolytic graphite sheets (PGSs) interposed in the compression direction between the core and the top plate and between the core and the bottom plate,
- wherein:
- the preferred direction of thermal conduction and the compression direction are aligned and a total height of the core and the PGSs in the compression direction exceeds a corresponding height of the stoppers with the PGSs uncompressed, and
- the screws engage with the stoppers such that the top plate impinges on the stoppers and the PGSs are compressed whereby the PGSs act as a thermal interface material (TIM) between the core and the top plate and between the core and the bottom plate in the compression direction aligned with the preferred direction of thermal conduction,
- wherein the heat spreader further comprises additional PGS lining the stoppers and oriented to lie along the compression direction.
9 more elements
A heat spreader, comprising:
- a core of orthotropic material having a preferred direction of thermal conduction;
- an
- encapsulant;
- and
- pyrolytic graphite sheets (PGSs) interposed between the core and the encapsulant in a compression direction aligned with the preferred direction of thermal conduction,
- the PGSs being compressed by the encapsulant to a compressed state to act as a thermal interface material (TIM) between the core and the encapsulant in the compression direction,
- wherein:
- the compressed state of the PGSs is characterized in that the PGSs are compressed to a predefined degree of compression,
- the heat spreader further comprises stoppers configured to halt further compression of the PGSs in the compression direction beyond the predefined degree of compression, and
- the heat spreader further comprises additional PGS lining the stoppers and oriented to lie along the compression direction.
7 more elements
A method of assembling a heat spreader, the method comprising:
- providing a core of orthotropic material having a preferred direction of thermal conduction;
- arranging the core between top and bottom plates in a compression direction aligned with the preferred direction of thermal conduction;
- interposing pyrolytic graphite sheets (PGSs) between the core and the top plate and between the core and the bottom plate in the compression direction;
- and
- forming, around the core and the PSGs, an encapsulant comprising the top and bottom plates and stoppers disposed on the bottom plate and with which the top plate impinges,
- wherein:
- following the interposing and prior to the forming, the PSGs are in an uncompressed state,
- the forming of the encapsulant comprises compressing the PGSs to a compressed state such that the PGSs provide a thermal interface material (TIM) between the core and the top plate and between the core and the bottom plate, and
- the method further comprises wherein the heat spreader further comprises lining the stoppers with additional PGS oriented to lie along the compression direction.
6 more elements
Dependencies are inferred from the claim text.